Ancient Pueblo Indians brewed their own brand of corn beer, a new study suggests, contradicting claims that the group remained dry until their first meeting with the Europeans.

Archaeologists recently found that 800-year-old potsherds belonging to the Pueblos of the American Southwest contained bits of fermented residue typical in beer production.

Before the discovery, historians thought a pocket of Pueblos in New Mexico did not have alcohol at all, despite being surrounded by other beer-making tribes, until the Spanish arrived with grapes and wine in the 16th century.

The tests were done using a highly sensitive set of scanning technologies at Sandia National Laboratories, a U.S. government facility that usually employs the gadgetry for national defense.

Pueblo not a desert island
A thousand years ago, traditional Native American farming villages were already scattered across parts of New Mexico, Arizona and northern Mexico, divided among several tribes including the Apache, Pueblo, Navajo and the Tarahumara.

Many of the tribes living in Mexico and some in Arizona are known to have produced a weak beer called tiswin, made by fermenting kernels of corn, but no evidence has ever been found that the same thing happened in New Mexico.

"There’s been an artificial construct among archeologists working in New Mexico that no one had alcohol here until the Spanish brought grapes and wine. That’s so counter-intuitive. It doesn’t make sense to me as a social scientist that New Mexico would have been an island in pre-Columbian times," said Glenna Dean, an archaeologist who approached Sandia Laboratories for help with her research, which she conducts through her small business Archeobotanical Services.

Tests found 800-year-old beer dregs
To test her thinking, Dean brought potsherds belonging to ancient New Mexican Pueblos, pots from modern Tarahumaran groups where tiswin is still brewed and pots in which Dean herself concocted the brew to Sandia Laboratories for comparison.

Sandia scientists analyzed the samples using gas chromatography and mass spectrometry, technologies that can identify the presence of organic compounds and are used in national security to detect chemical, biological and other hazardous agents.

Common, microscopic leftovers of alcoholic compounds were found across all three, said Sandia researcher Ted Borek, indicating that the ancient pots were likely used for the same purpose — fermentation — as the modern ones. The results were presented by Borek in a talk at a recent Materials Research Society meeting in Boston.

"There appear to be consistencies across the modern home brew and Tarahumaran pots," Borek said, who cautioned that they "have not found that ‘smoking gun’ that definitely provides evidence of intentional fermentation. It’s always possible that corn fermented in a pot without the intent of the owner."

More research will be conducted on the pots to rule out accidental fermentation. Given the success of Dean's experiment, mass spectrometry and gas chromatography are expected to be sought out for more archaeological studies at Sandia Laboratories, the scientists said.